Telephone communication today is virtually ubiquitous, particularly in developed countries such as the United States. In most local exchange carrier telephone networks, particularly in residential settings, the customer premises wiring connects telephone station equipment to a central office switching system via a hardwired line. The network line to the customer premises may take many different forms in the field, but most telephone circuit installations still utilize a twisted wire pair type loop or drop for at least the last 500 feet into the customer premises. A network interface device in turn connects the drop cable to the customer premises wiring. The customer premises equipment (CPE), e.g. telephone stations and the like, connects to the customer premises wiring. This system is used for analog and digital incarnations of plain old telephone service (POTS) as well as for broadband communications over the telephone wiring, such as the various forms of broadband digital subscriber line (xDSL) service.
In most current deployments, the network interface device (NID) is a relatively simple device providing terminals for interconnecting the drop cable wiring from the network to the customer premises wiring. There have been proposals to add some “smart” or intelligent control capabilities to a NID, for example, to allow switching to a wireless communication in the event of a failure or cut of the drop cable (U.S. Pat. No. 5,751,789 to Farris et al.). As another example, U.S. Pat. No. 6,047,063 to Perry discloses a smart NID with the capability to switch from a first wire pair serving as the drop to a second wire pair for the drop, for example, to replace a damaged pair or to migrate service to a pair that better supports a service upgrade (e.g. if the subscriber upgrades from POTS to ISDN or an xDSL service).
Modern society continues to create exponentially increasing demands for communication of various forms of information. Desired services now range from simple text and voice communications up through broadband communications for video and multimedia applications. Increasingly, there is a need for a carrier network architecture capable of providing a variety of communication services, for example, ranging from voice grade telephone service to packet switched data services and broadband digital communications services.
The existing telephone network has fostered much of the growth in telecom services and applications thereof. However, the current architecture of that network, essentially designed in the 1960s, uses time division multiplex technology optimized for voice grade telephone services over copper wiring to the end users. The design of the telephone network, optimized for cost effective transport of voice calls, imposes a severe bandwidth limitation. Although many users are satisfied with the services of such a network, increasingly many customers are exploring competing options for obtaining communication services that involve much higher-rate digital communications.
Consequently, telephone carriers are faced with a need to migrate their existing services up to a higher capacity network that will support those services as well as the newer broadband digital services demanded by sophisticated customers. These trends are forcing telephone service carriers to migrate to a fast packet network architecture supporting broadband services. Existing end office switches simply cannot handle broadband services and are not readily adaptable to the fast packet operations. A number of proposals have been suggested to upgrade or replace the local telephone network, to provide the newer types of services.
For example, U.S. Pat. No. 5,864,415 to Williams et al. discloses a fiber-to-the-home network architecture. Optical fiber extends from the central office to an intelligent interface device within the home. The intelligent interface device provides interconnections to various analog and digital communication media within the home, including a telephone line and a data network (10BaseT cable). The Williams Patent suggests use of a ring architecture, for the higher-level portions of the network.
U.S. Pat. No. 5,541,917 to Robert D. Farris discloses an advanced intelligent network type communication system, which provides both telephone service and broadband service. The disclosed architecture includes service switching point (SSP) type telephone central offices, signaling transfer points (STPs) and a central controller implemented as an integrated service control point (ISCP). At least some services are provided via SSP type host digital terminals (HDTs) and/or asynchronous transfer mode (ATM) type SSP switches. The HDT, for example, communicates via optical fiber to optical network units (ONUs) at the curbside, and it communicates with higher level elements of the network via fiber.
Recent proposals for fiber optic metro area networks, such as that described in the white paper: Sistanizadeh, “Managed IP Optical Internetworking, a Regional IP-over-Fiber Network Service Architecture,” © 2000 Yipes Communications, Inc. (http://www.yipes.com/technology/whitepapers.html), suggest a multi-layered optical fiber ring network. A first level ring connects Ethernet switches that provide access for customer equipment to Ethernet switches in the distribution plane. A next level ring connects a number of the distribution switches, and this ring connects to a switch at a hub on the national ring network.
The existing network interface devices, such as those discussed earlier, do not adequately support the wide range of different types of customer premises media that the customers may want to use for their communications through these and other designs for more advanced communication networks. The existing network interface devices are not readily adaptable to customer selection or even customer change/addition of media within the premises. Also, the existing network interface devices, even those that are somewhat smart, have not been readily programmable. With increasingly sophisticated network services and increasingly sophisticated customer applications, both the carrier and the customers may have a desire and potentially a need to install and from time to time change programming at the demarcation between the premises equipment and the network, and the existing devices have not offered adequate programming capabilities.
There are a number of customer premises devices on the market for providing home routing or home gateway capabilities. These devices communicate via one or more wide area networks and provide a routing or gateway interface between such networks and end user equipment at the customer premises. Some of these devices support multiple communications types within the premises, e.g. data and telephone communications, in some cases, via more than one customer premises medium. However, these devices are purely customer premises equipment purchased and installed by the customer within the premises. They do not reside at or provide an interface across the line of demarcation at the edge of the local carrier's network. Also, as customer equipment, these devices have been programmable by the customers but not the local carrier.
Hence, a need still exists for a network interface device for use at the edge of a carrier's digital broadband network that provides digital broadband communication services, where the network interface device is flexible and programmable, both to meet needs of the customer and to meet needs of the carrier.